Oxygen sorbent compositions and methods of using same

ABSTRACT

Compositions and methods useful for oxygen sorption and other uses are presented, the compositions A composite material comprising components (A) and (B), wherein component (A) is selected from crystalline ceramic materials capable of forming a stable, reversible perovskite crystal phase at elevated temperatures (T&gt;500° C.), and combinations thereof, and component (B) comprises a metal selected from rhodium (Rh), platinum (Pt), palladium (Pd), nickel (Ni) and silver (Ag), and combinations and alloys of these metals.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. provisional application No.60/531,780, filed Dec. 22, 2003, which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is generally related to the field of oxygen sorbentmaterials.

2. Related Art

Materials having the ability to absorb oxygen are useful in manyindustries, for example enrichment of oxygen from air or othermulticomponent fluid. One useful class of crystalline materials is theso-called mixed ionic-electronic conductors (MIEC). These materials haveexhibited enhanced sorption, as well as enhanced ionic and electronicconductivities, particularly their oxide-ion mobility andoxygen-(O₂)-storing capacities. High-temperature non-stoichiometricdefects (such as oxide-ion vacancies or interstitial oxygen sites) inthe crystal-lattice allow the materials to temporarily sorb oxygen athigh-temperature for oxygen enrichment of gas streams, as well as forcatalytic transformations of other compounds using the oxygen that istemporarily absorbed.

Potential applications of MIEC materials have been documented:production of syngas and H₂; partial oxidation of light hydrocarbons;production of pure O₂ (with a view toward replacing, possibly, cryogenicdistillation); production of O₂-enriched gas mixtures; variousenvironment-related solutions; and solid-oxide fuel cells and sensors(cf, for example, P. J. Gellings and H. J. M. Bouwmeester, Solid StateElectrochemistry, CRC Press, Boca Raton, 1996; H. Ullman, KeramischeZeitschrift, 53 (2001) 100-107; S. J. Skinner and J. A. Kilner,materialstoday (March 2003) 30-37. Specifically, Ion-Transport-Membrane(ITM) technologies for O₂ separation and syngas production are underquickly progressing development.

Technologies other than ITM, such as cyclic high-temperaturesorption-desorption processes based on O₂ partial-pressure swings, havegained considerable interest. Cyclic O₂-recovery processes that utilizespecific ceramic materials, such as K₂NiF₄ as sorbent/catalyst havinghigh-temperature non-stoichiometric defects are being developed. Theseprocesses are referred to as ceramic autothermal recovery processes, orCAR processes, to be discussed further in the Description. They consistof alternately passing air and another medium (or applying vacuum)through pellets or granules of the material in a fixed-bedconfiguration, with cycle times of the order of minutes or less. Oxygenretained in the solid material during the air contacting step isreleased by decrease in O₂-partial pressure via application of vacuum,steam, carbon dioxide, steam-carbon dioxide mixtures, flue-gas mixturesor other appropriate means, to generate an O₂-enriched stream, which isused as feed to other systems, into which CAR could be integrated, e.g.,combustion processes.

Key advantages of CAR over ITM processes are ease of materialfabrication, plant design and process execution using traditional unitoperations. Preliminary estimates indicate significant economic benefitscompared to the traditional cryogenic air separation, due to lowerenergy consumption. On the other hand, cryogenic air separation plantsare well understood and, despite their high operating costs, industrymomentum is geared toward designing these plants cost-effectively, andthis leads to reduced engineering and design costs, and inherent safetybuilt up over time.

One of the key technical issues and risks of the CAR process for O₂enrichment relates to material development. Of the MIEC materials ofinterest, perovskites and perovskite-like materials have attractedattention in the past. The process-related crystal-structure oxide-ion,O²⁻, deficiency can be exemplified by perovskite-type oxides, whichoriginally referred to the mineral CaTiO₃. Today, “perovskite” denotes aseries of oxygen-containing compounds with a unique general crystalstructure, ABO₃, with high-temperature O²⁻ vacancies, denoted by thesymbol δ, which obeys the general formula ABO_(3-δ). The “A”-sitecations can be rare earth, alkaline earth, alkaline and other largecations such as Pb²⁺, Bi³⁺, or Ce⁴⁺, and the “B”-site cations can be 3d,4d, or 5d transition-metal cations. Multiple cation-type occupations ofthose two sites are possible. Framework sites “A” and “B” aredodecahedral and octahedral, respectively, cf., L. G. Tejuca and J. L.Fierro, Properties and Applications of Perovskite-type Oxides, MarcelDekker, New York, 1993.

A standard cubic high-temperature perovskite phase remains stable andreversible with regard to changes of δ within a certain range: The valueδ could be as high as 0.25, but as a rule δ=0.05-0.25 (although highervalues have been reported), at elevated temperature and low oxygenpartial pressure, i.e., δ is a function of temperature and partialpressure of oxygen. On the other hand, perovskite stability is governedby cation radii of lattice metals in various valence states combinedinto a parameter “t” called “tolerance factor”, cf., Z. Shao, et al.,Sep. Purif Technol., 25 (2001) 419-42. A perovskite structure can onlybe formed if t ranges from 0.75-1. These circumstances have set limitsto the performance potential of perovskites in O₂-recovery and relatedprocesses. Tereoka et al. described the materialLa_(1-x)Sr_(x)Co_(1-y)Fe_(y)O_(3-δ) as a medium for oxide-ion permeationwith excellent performance at high temperature (Y. Tereoka et al.,Chemistry Letters, (1985) 1367-1370; 1743-1746). In this case, the O₂permeation is driven by the O₂-partial-pressure difference between thetwo sides of the membrane, and it results from oxygen-ion transportthrough the vacant sites in the lattice structure. Significant effortshave been directed to the investigation of the fabrication andutilization of these materials as O₂-transport membranes for gasseparation and reaction. Mazanec, et al., (U.S. Pat. No. 4,933,054) wereawarded a patent in this area in 1990. One recent study ofSrCo_(0.4)Fe_(0.6)O_(3-δ) reported, however, a decrease in oxygenpermeability through samples that were purposely made stronger byaddition of up to 9 wt % ZrO₂, where the Zr⁴⁺ cations replaced some ofthe B site cations. Yang, et al., Effect of the Size and Amount of ZrO ₂Addition on Properties of SrCo _(0.4) Fe _(0.6) O _(3-δ) , AIChEJournal, Vol. 49, Issue 9, pages 2374-2382 (2003).

Desorption of O₂ from La_(1-x)Sr_(x)CoO_(3-δ) was studied and reportedby Nakamura et al. (Chemistry Letters, (1981) 1587-1581) in 1981. Later,Teraoka et al. (Chemistry Letters, (1985) 1367-1370) examined O₂sorption properties of La_(1-x)Sr_(x)Co_(1-y)Fe_(y)O_(3-δ). Theyobserved that considerable amount of O₂ was desorbed from this class ofoxides as temperature was increased from 300° C. to 1100° C., and wasabsorbed as temperature was decreased. Mizusaki et al. (J. Solid StateChemistry, 80 (1989) 102) measured the oxygen non-stoichiometry of theperovskite-type oxide La_(1-x)Sr_(x)CoO_(3-δ) as function oftemperature, Sr content (x) and O₂-partial pressure. Lankhorst andBouwmeester (J. Electrochem. Soc., 144 (1997) 1268) measured the oxygennon-stoichiometry of La_(0.8)Sr_(0.2)CoO_(3-δ). Zeng and Lin (SolidState Ionics, 110 (1998) 209-221) investigated O₂-sorption anddesorption rates of a La_(0.2)Sr_(0.8)CoO_(3-δ) sample subjected tosudden changes of O₂-Partial pressure at constant temperatures. Theyfound that this rate could be correlated to a linear-driving force ofthe deviation of oxygen-vacancy concentration in the bulk phase of thesample from its corresponding thermodynamically equilibrated one.

Few patents have been issued for processes using the O₂-sorptionproperties of perovskite-type oxides for gas separation andpurification. Doi et al., KoKai Patent No. Hei 5 (1993)-4044, 1993)disclose using a perovskite-type oxide, ABO_(3-δ), as high-temperatureO₂ sorbent to remove O₂-containing impurities, such as NO_(x) by meansof a TSA technique to regenerate the sorbent. A Chinese patentapplication by Yang, et al., Appl. No. 99 1 13004.9, describes amaterial, Ba_(0.5)Sr_(0.5)CO_(0.8)Fe_(0.2)O_(3-δ), with very highconcentration of oxygen vacancies. The CAR concept, developed by Lin, etal., U.S. Pat. No. 6,059,858, also uses perovskite-type oxides assorbents to separate O₂ from an O₂-containing stream, particularly air,by a type of mixed TSA-PSA process. This patent also discloses methodsof sorbent regeneration using CO₂ or steam as the purge gas.

U.S. Pat. No. 6,143,203 describes CAR technology extended to the area ofhydrogen and synthesis-gas production using perovskite-type oxidesorbents. See also U.S. Pat. Nos. 6,379,586 and 6,464,955. A materialpatent of common assignment hereto has also been applied for: SupportedPerovskite-Type Oxides and Methods for Preparation Thereof by Zeng, etal., U.S. Pub. Pat. Appl., U.S. 2002/0179887 A1 (2002).

As mentioned, the ability of perovskite and perovskite-like materials tofunction as commercial sorbents has limits. There have been recentefforts to improve the O₂-sorption performance of these materials, butwith limited success. U.S. Pat. No. 6,772,501 discloses composites ofmetals and ion conductors; U.S. Pat. No. 6,740,441 discloses usingperovskites to thin-film coat “current collects” (metal screens or mesh)in solid oxide fuel cells, and other devices, and gas separations arementioned; U.S. Pat. Nos. 6,641,626 and 6,471,921 disclose MIECconducting membranes for HC processing, and disclose ceramic membraneswhich have good ionic and electrical conductivity, plus excellentstrength under reactor operating conditions. The compositions comprise amatrix of MIEC (especially brownmillerite) with one or more secondcrystal phase, non-conductive, which enhances strength; U.S. Pat. No.6,541,159 discloses O₂-separation membranes having an array ofinterconnecting pores and an OH⁻ ion conductor extending through thepores, and an electrical conductor extending through the pores, discretefrom the OH⁻ ion conductor; U.S. Pat. No. 6,440,283 discusses formingpellets, powders, and two layer structures of La/Sr oxides; U.S. Pat.No. 6,146,549 discloses La/Sr ceramic membranes for catalytic membranereactors with high ionic conduction and low thermal expansion; U.S. Pat.Nos. 5,509,189 and 5,403,461 discuss solid solutions of pyrochlorecrystal phase and perovskite crystal structures.

Despite improvements in the art, the need remains for compositions,which take better advantage of the excellent O₂-sorption andpermeability properties of perovskites and perovskite-like materials,while exhibiting enhanced durability, so that the materials may be usedcommercially.

SUMMARY OF THE INVENTION

In accordance with the present invention, composite materials andmethods of use are presented which reduce or overcome many of theproblems of previously known materials.

A first aspect of the invention relates to composite materials,specifically composite materials comprising components (A) and (B),wherein component (A) is selected from crystalline ceramic materialscapable of forming a stable, reversible perovskite crystal phase atelevated temperatures (T>500° C.), and combinations thereof, andcomponent (B) is a metal selected from rhodium (Rh), platinum (Pt),palladium (Pd), nickel (Ni) and silver (Ag), and combinations and alloysof these metals.

Desirable crystalline ceramic materials capable of forming a stable,reversible perovskite crystal phase at elevated temperatures includeperovskites, perovskite-like compounds, and pyrochlores.

Perovskites useful in the invention are those within general formulas(1), (2), and (3):A_(x)B_(y)O_(3-δ),  (1)A_(x)A′_(x′)B_(y)B′_(y′)O_(3-δ), and  (2)A_(x)A′_(x′)A″_(x″)B_(y)B′_(y′)B″_(y″)O_(3-δ),  (3)and combinations thereof, wherein:

-   -   A, A′, and A″ are independently selected from ions of atoms        having atomic number ranging from 57-71, inclusive, a cation of        yttrium, ions of Group 1 atoms, ions of Group 2 atoms, and        combinations of two or more, where Group 1 and Group 2 refer to        the periodic table of elements;    -   B, B′, and B″ are independently selected from d-block        transition-metal ions selected from Mn, Cr, Fe, Co, Ni, and Cu;    -   x, x′, x″, y, y′, and y″ are each real numbers ranging from 0 to        1.0;    -   x+x′+x″=0.8-1.0; y+y′+y″=1.0; and δ ranges from about 0.05 to        about 0.30;    -   with the provisos that:        -   (1) when a Co ion is present at a plurality of B sites, then            at least some of the B′ sites are occupied by Fe ions, and            at least some of the B″ sites are occupied by Ni ions;        -   (2) when a Cu ion is presented at a plurality of B sites,            then at least some of the B′ and B″ sites are occupied by            one or more of Mn ions, Cr ions and Fe ions; and        -   (3) when proviso (1) is true, then at least one other            compound within general formulas (1), (2), and (3) is            present.

Perovskite-like compounds useful in the invention are those withingeneral formulas (4), (5), (6), (7), (8), and (9):A₂BO_(4-δ)  (4)A₂B₂O_(5-δ)  (5)AO(ABO_(3-δ))_(n)  (6)AM₂Cu₃O_(7-δ)  (7)Bi₄V_(2(1-x))Me_(2x)O_(11-3x),  (8)A″B″O₃  (9)wherein:

-   -   A is independently selected from ions of atoms having atomic        numbers ranging from 57-71, inclusive, a cation of yttrium, ions        of Group 1 atoms, ions of Group 2 atoms, and combinations of two        or more, where Group 1 and Group 2 refer to the periodic table        of elements;    -   B is independently selected from d-block transition metal ions;    -   A″ is an ion of Na or Li, and B″ is an ion of W or Mo;    -   M is a metal cation selected from cations of Group 2 atoms of        the periodic table of elements;    -   Me is a metal cation selected from cations of Cu, Bi, and Co        atoms;    -   x is a real number ranging from 0.01 to 1.0;    -   n ranges from 1 to about 10; and    -   δ ranges from about 0.05 to about 0.30.

Pyrochlores useful in the invention are those within general formula(10):A₂B₂O_(7-δ)  (10)wherein:

-   -   A is independently selected from ions of atoms having atomic        numbers ranging from 57-71, inclusive, a cation of yttrium, ions        of Group 1 atoms, ions of Group 2 atoms, and combinations of two        or more, where Group 1 and Group 2 refer to the periodic table        of elements;    -   B is independently selected from d-block transition metal ions;        and    -   δ ranges from about 0.05 to about 0.30.

One group of composites of the invention are those wherein A is an ionof atoms having atomic number ranging from 57-71, inclusive; A′ is an Srion; and B and B′ (when present) are selected from Ni, Co and Fe ions.Another set of composites within the invention are those whereincomponent (A) comprises a crystalline ceramic oxide within generalformula (7) AM₂Cu₃O_(7-δ) and component (B) is a metal selected from Rh,Pt, Pd, Ni, Ag and combinations thereof.

Composites of the invention may be formed as structured particles havinga particle size ranging from about 0.01 to about 100 microns in largestdimension, or range from about 0.1 to about 50 microns.

Composites of the invention, when used as oxygen separation media, maybe supported on (or serve as supports for) an “active” matrix selectedfrom porous inorganic materials that are stable at temperatures rangingfrom about 500 to about 1000° C. In this form the inventive compositionsmay be referred to as supported composites. “Active”—as that term isused when referring to support or matrix materials—means that even thesupporting material acts in the oxygen sorption and transport. Compoundsof general formula M′O_(n′) may be supported by the composites of theinvention. Compounds within the general formula M′O_(n), referred to as“binary metal oxides”, mean a single metal element that assumesdifferent oxidation states within the oxygen partial pressure range ofthe CAR process, enabling the metal oxides to release oxygen atdifferent partial pressures of oxygen in CAR processes. In the binarymetal oxides, M′O_(n), M′ is a metal of the d block transition metalsthat changes its oxidation state. Metals may be Cu, Co, Ni, Bi, Pb, V,Mn, and Cr, the oxides of which release oxygen by changing their crystalphase or by their reduction up to the metal. In their pure states, thebinary metal oxides do not form stable ceramic shapes because of crystalphase transformations. However, in combination with an active support ormatrix oxide (perovskite materials within general formulas (1), (2), or(3), perovskite-like materials within general formulas (4), (5), (6),(7), (8), and (9), and pyrochlores within general formula (10)),stability of the binary metal oxides can be enhanced, while extendingthe oxygen sorption/desorption capacities of the matrix compositions.Other suitable active support materials include apatite compositions.

Supported composites of the invention may be shaped, structured articlesof manufacture, having shape selected from beads, pellets, saddles,rings, pyramids, extrudates with any cross sectional shapes with orwithout holes, honey-combs with uniform channels and monoliths withrandom porosity and foam structure, and the like. The inorganic supportmay be a porous inorganic support comprising a plurality of pores, asfurther described herein.

Composites of the invention may be coated on one or more non-poroussupport materials to achieve an increase in performance, and enhancementof thermal and mechanical properties of the composition.

Composites of the invention desirably comprise component (A) coated orimpregnated with one or metals from those in component (B), in otherwords, a perovskite, perovskite-like compound, or pyrochlore coated orimpregnated with a metal selected from Rh, Pt, Pd, Ni, Ag andcombinations and alloys thereof.

A second aspect of the invention are methods of separating a gascomponent from a mixture of gases by either of pressure swingadsorption, thermal swing absorption, or combination thereof, comprisingcontacting a gas mixture with a composite of the invention. Methods ofthe invention include converting a light hydrocarbon (C₅ or less) intohydrogen and carbon monoxide by contacting one or more hydrocarbons witha composition of the invention, including reactions of partialoxidation, steam reforming, auto-thermal reforming, and the like, inprocess modes selected from batch, semi-continuous, continuous or cyclicoperations. The reactions may be carried out in well-known bed-typereaction vessels, where the bed of particles is fluidized,semi-fluidized, or non-fluidized.

Thus, the present invention provides for novel materials and methods ofuse, specifically modified mixed ionic-electronic conductor (MIEC)materials (either alone or as composites with active oxygen exchangesupport materials) with enhanced performance in sorption, catalyticprocesses, and the like. The inventive composites owe their ionic andelectronic conductivities, particularly their oxide-ion mobility andO₂-storing capacities, to high-temperature non-stoichiometric defectssuch as oxide-ion vacancies—or interstitial oxygen sites—in thecrystal-lattice structure of the solids, and also on changed valencestates of a selected series of transition metals, which lead todifferent oxides of one and the same metal. These materials will havestrong potential for high-temperature processes that utilize theO₂-storing/releasing properties for purposes of the enrichment of O₂ ingas streams but also for multi-fold catalytic transformations of othercompounds. The inventive composites may also be formed into chemicallyand mechanically robust ceramic composites such as sorbent and membranematerials with high O₂ capacities (in the case of adsorbents) and highO₂ permeation fluxes (in the case of membranes). This enables the designof high-performance structured ceramics of regular or random shapes,allowing for high performance in O₂ enrichment and, at the same time,the ability to withstand the expected operating conditions in largescale plants, and be cost-effective in addition. The inventivecomposites may be utilized advantageously for high-temperature CAR-typePVSA and TSA processes (and also for other related applications) toproduce substantially pure O₂, syngas and H₂ (at small and large scale),as well as O₂ and fuel in integrated process schemes, for example,so-called oxy-fuel processes and many other processes.

Further aspects and advantages of the invention will become apparent byreviewing the detailed description of the invention that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 illustrate graphically the concept of working capacity forsorbent materials of the invention; and

FIG. 3 is a schematic representation of a ceramic autothermal recoveryprocess of the invention.

DETAILED DESCRIPTION OF THE INVENTIONS

Novel materials that reversibly deliver O₂ in CAR processes and othermethods of use are now described in further detail. Primary attention ispaid to new composites of two or more oxides that act reversibly withhigh exchange rate and high capacity for O₂ over a O₂-partial pressureregion between 5 and 0.01 atmosphere. Beside these parameters, theirthermodynamic and long-time mechanical stability under the conditions ofcommercial processes, with maintenance of both the desired crystalstructure and secondary ceramic shape, specifically by consideringthermal expansion coefficients as important material-specificparameters, are accounted for.

Composites of the invention may generally be categorized as combinationsof components (A) and (B), wherein component (A) is selected fromcrystalline ceramic materials capable of forming a stable, reversibleperovskite crystal phase at elevated temperatures (T>500° C.), andcombinations thereof, and component (B) is a metal selected from rhodium(Rh), platinum (Pt), palladium (Pd), nickel (Ni) and silver (Ag), andcombinations and alloys of these metals. As mentioned in the backgroundsection, a standard cubic high-temperature (about 500-1000° C.)perovskite phase remains stable and reversible with regard to changes ofδ within δ=0.05-0.25 at elevated temperature and low oxygen partialpressure. On the other hand, perovskite stability is governed by cationradii of lattice metals in various valence states combined into aparameter “t” called “tolerance factor”, and a perovskite structure canonly be formed if t ranges from 0.75-1. These circumstances have setlimits to the performance potential of perovskites in O₂-recovery andrelated processes. Attempts to extend the limits of useful perovskiteshave failed, at least as far as oxygen permeability is concerned. Forexample, when a perovskite material was purposely made stronger byaddition of ZrO₂, where the Zr⁴⁺ cations replaced some of the B sitecations, the material was stronger, but the oxygen permeabilitydecreased. Yang, et al., Effect of the Size and Amount of ZrO ₂ Additionon Properties of SrCo _(0.4) Fe _(0.6) O _(3-δ) , AIChE Journal, Vol.49, Issue 9, pages 2374-2382 (2003).

The inventors herein have discovered that composite materials of theinvention overcome some or all the limitations of previous compositionsin enhancing oxygen permeability and oxygen trapping ability. As may beseen from the above general description of composites of the invention,the key to the effectiveness of the composites of the invention lies inthe selection of the B site cations; in particular, it appears that theability of Fe, Co, Ni, Cu, Cr and Mn cations to be present in more thanone oxidation state in the crystal lattice at high temperatures allows,the compositions of the invention to be particularly useful intemporarily absorbing oxygen, especially in certain unexpectedcombinations of perovskites, perovskite-like compounds, and pyrochloreswith the metals Rh, Pt, Pd, Ni, and Ag. It is also theorized that theionic radii of the selected A and B site cations in their variousoxidation states, and the fluctuation between these states and radii,perhaps help in the generation of oxide ion vacancies in the crystallattice of perovskites, perovskite-like compounds and pyrochlores usefulin the composites of the invention. Furthermore, it is theorized thatthe presence of metals Rh, Pt, Pd, Ni, and Ag in close proximity toperovskite structures within the composites of the invention helps insurface effects.

The valency states of the various transition metals deemed useful in thecomposites of the invention, and the ionic radii of the most stable ion,are presented in Table 1, in accordance with R. D. Shannon, Acta Cryst.,A32 (1976) 751-767. The ionic and electronic conductivities of thesecompositions, particularly their oxide-ion mobility, andoxygen-(O₂)-storing capacities that are based on high-temperaturenon-stoichiometric defects such as oxide ion vacancies, or interstitialoxygen sites, in the crystal-lattice structures of these solids, makescomposites of the invention particularly useful in oxygen separation.TABLE 1 Valancy States and Ionic Radii Atomic Number Symbol PossibleOxidation States Ionic radii (pm)* 24 Cr 2, 3*, 4, 5, 6 62 25 Mn 7, 6,4, 3, 2* 67 26 Fe 2, 3* 55 27 Co 2*, 3 65 28 Ni 2*, 3 69 29 Cu 2*, 1 73*Most stable cation

Perovskites useful in composites of the invention include those whereinA is an ion of atoms having atomic number ranging from 57-71, inclusive;A′ is an Sr ion; and B and B′ are selected from Ni, Co and Fe ions.Perovskite oxides useful in the invention within general formula (2)A_(x)A′_(x′)B_(y)B′_(y′)O_(3-δ) are those wherein 0.5<x<1, 0.1<x′<0.5,0.2<y<0.8, and 0.2<y′<0.6. Some specific perovskites, perovskite-likeoxides, and pyrochlore oxides useful in the invention include those inTable 2. TABLE 2 Perovskites, Perovskite-like and pyrochlore compoundsPerovskites: A_(x)A′_(x′)B_(y)B′_(y′)O_(3−δ) (2)La_(0.6)Sr_(0.4)Co_(0.8)Fe_(0.2)O_(3−δ,)Sr_(0.9)Ce_(0.1)Fe_(0.8)Co_(0.2)O_(3−δ,)La_(0.2)Sr_(0.8)Co_(0.6)Fe_(0.4)O_(3−δ,)Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)Ca_(0.5)Sr_(0.5)Mn_(0.8)Fe_(0.2)O_(3−δ)Ca_(0.45)Sr_(0.45)Mn_(0.8)Fe_(0.2)O_(3−δ)La_(0.8)Sr_(0.2)Ni_(0.4)Co_(0.4)Fe_(0.2)O_(3−δ)La_(0.6)Sr_(0.4)Cr_(0.2)Fe_(0.8)O_(3−δ,) Perovskite-related: A₂BO_(4−δ)(4) La₂CoO_(4−δ) La₂MnO_(4−δ) La₂FeO_(4−δ) Sr₂CuO_(4−δ) Sr₂MnO_(4−δ)A₂B₂O_(5−δ) (5) La₂Co₂O_(5−δ) La₂Mn₂O_(5−δ) Sr₂Cr₂O_(5−δ) Ce₂Mn₂O_(5−δ)AO(ABO_(3−δ))_(n) (6) LaO(LaCuO_(3−δ))₅ SrO(LaCrO_(3−δ))₆GdO(SrFeO_(3−δ))₅ CeO(LaNiO_(3−δ))₆ YO(YMnO_(3−δ))_(n)CeO(CeMnO_(3−δ))_(n) AM₂Cu₃O_(7−δ) (7) KBa₂Cu₃O_(7−δ) NaBa₂Cu₃O_(7−δ)LaBa₂Cu₃O_(7−δ) MgBa₂Cu₃O_(7−δ) SrBa₂Cu₃O_(7−δ)Y_(0.5)La_(0.5)BaCaCu₃O_(7−δ) Y_(0.8)La_(0.2)Ba_(0.8)Sr_(1.2)Cu₃O_(7−δ)Y_(0.7)La_(0.3)Ba_(0.8)Sr_(1.2)Cu₃O_(7−δ)Y_(0.9)La_(0.1)Ba_(0.6)Ca_(0.6)Sr_(0.8)Cu₃O_(7−δ)Bi₄V_(2(1−x))Me_(2x)O_(11−3x,) (8) Bi₄VCuO_(9.5)Bi₄V_(0.6)Co_(1.4)O_(8.9) Bi₄V_(1.4)Bi_(0.6)O_(10.1)Bi₄V_(1.6)Cu_(0.4)O_(10.4) A″B″O₃ (9) LaFeO₃ SrCoO₃ SrFeO₃ PyrochloresA₂B₂O_(7−δ) (10) Mg₂Fe₂O_(7−δ) Mg₂Co₂O_(7−δ) Sr₂Mo₂O_(7−δ)

Perovskites within general formulas (1)-(3), perovskite-like compoundswith general formulas (4)-(9) and pyrochlores within general formula(10) may be present with one or more metals selected from Rh, Pt, Pd,Ni, Ag and combinations and alloys thereof in a variety of formats,including, but not limited to, solid solutions, layered compositions,randomly mixed compositions, and the like. For example, a perovskite maybe present with a metal as intergrown layers, as discrete layers, or asthe metal deposited on the perovskite by any known deposition means,such as chemical vapor deposition, physical vapor deposition,plasma-enhanced chemical vapor deposition, various sputteringprocedures, electrochemical deposition, and the like. As examples ofthese:

-   -   platinum electrochemically deposited on        Y_(0.5)La_(0.5)BaCaCu₃O_(7-δ);    -   platinum sputter deposited on        Y_(0.8)La_(0.2)Ba_(0.8)Sr_(1.2)Cu₃O_(7-δ);    -   rhodium chemical vaspor deposited on Mg₂Fe₂O_(7-δ);    -   90% platinum/10% rhodium alloy electrochemically deposited on        La_(0.6)Sr_(0.4)Co_(0.8)Fe_(0.2)O_(3-δ),        and the like. Multiple layers are possible, with alternating        layers of two or more crystalline ceramic oxides with metals.        Such arrangements allow for (i) buffering thermal-mechanical        properties, (ii) increasing the surface-reaction rate by        enhancing the accessible surface and the influence of        grain-boundary region effects, and (iii) synergistic effects for        increasing the “working capacity” of the materials. Dual phases        of a crystalline ceramic oxide with one or more metal phases        comprise another embodiment.

The meaning of the process parameter “working capacity” follows fromFIGS. 1 and 2 that illustrate by sorption-isotherm schemes thesorption-process principles TSA (Thermal Swing Adsorption) and PSA(Pressure Swing Adsorption), respectively. A CAR process could bethought to be executed at conditions limited by these two principles.FIG. 1 illustrates graphically a pressure swing adsorption (PSA) scheme.(A similar figure would express a vacuum swing adsorption (VSA) scheme,which those of skill in the art will recognize is another method usefulin practicing the invention.) In a PSA scheme, adsorption of the desiredspecies (typically O₂) by pressure build-up at constant temperatureleads to point H. Desorption using either pressure decrease (or vacuum)or partial pressure decrease in the desired species (using a replacementor sweep gas) at constant temperature leads the system to point L. Theresulting difference is sorption uptake as shown at the ordinate is Δnover the difference in (partial) pressure Δp. The difference Δnrepresents the so-called “working capacity” (or desorbable amount oftarget species over a defined oxygen partial pressure range). This cycleis typically repeated one or a plurality of times. FIG. 2 illustratesgraphically a temperature swing adsorption (TSA) scheme. Adsorption ofthe desired species (typically O₂) by pressure build-up at constanttemperature T₁ leads to point H. Desorption using temperature increase,e.g., towards T5 with (or without) some pressure increase, leads thesystem to point L. Desorption may be supported by purge in conjunctionwith temperature increase using a fluid species that is less stronglysorbed than the target species. The resulting working capacity of thesorbent material is illustrated as the desorbed amount of targetspecies, Δn. This cycle is typically repeated one or a plurality oftimes.

Primary composites of the invention (comprising components (A) and (B))may be formed as particles having a particle size ranging from about0.01 to about 100 microns in largest dimension, or ranging from about0.1 to about 50 microns. The particles may be shaped articles ofmanufacture, having shape selected from beads, pellets, saddles, rings,pyramids, cubes, extrudates with any cross sectional shapes with orwithout holes, honey-combs with uniform channels and monoliths withrandom porosity and foam structure, and the like.

Composites of the invention may be made and characterized using standardceramic and metal deposition processing steps and equipment. Forexample, to make a composite of La_(0.6)Sr_(0.4)Co_(0.8)Fe_(0.2)O_(3-δ)and Pt metal, one might start with technical grade samples of each rareearth oxide and metal oxide required to makeLa_(0.6)Sr_(0.4)Co_(0.8)Fe_(0.2)O_(3-δ) Stoichiometric amounts of eachoxide required to produce La_(0.6)Sr_(0.4)Co_(0.8)Fe_(0.2)O_(3-δ) arewell mixed using an agate and pestle, then mixed or layered as desiredto form a green composite, and then fired at a high temperature, usuallyabout 1000° C. The fired oxide is then pressed together into the desiredshapes under pressure, and then sintered to make the dense material.Platinum may then be sputter-deposited onto the densified ceramic usingany known metal sputtering technique. The structure of the individualpowders and the final shaped articles may be studied using XRD employinga diffractometer such as that known under the trade designationD/Max-RB, available from Rigaku. Oxygen temperature-programmeddesorption equipment is readily available. A heating rate of 10° C./minis typical. Oxygen permeation of membrane materials may be studied usingknown gas chromatography (GC) techniques. For example, a disk of thesintered material may be sealed in the end of an alumina tube, one sideof the disk exposed to air, the other exposed to flowing helium. Theoutlet gas (He+O₂) is connected to the GC, for example a GC availablefrom Hewlett-Packard known under the trade designation HP5890A. The GCis calibrated frequently using standard gases. The O₂ permeation flux(J_(O2)) may be calculated from known equations, such as the following:J _(O2) =S/S°×P°×F/S _(m),where S is the oxygen area of the outlet gas, S° the oxygen area of thestandard gas, P° the percentage of O₂ in the standard gas, F the outletgas flow rate and S_(m) the effective inner surface area of the membranematerial.

The ratio of ceramic component (A) to metallic component (B) in thefinal composite will of course depend on the end use, including thephysical, chemical, and thermal environment the composite is exposed to,and the cycling of temperature and/or pressure that is expected to occurin various processes. Generally speaking, the weight ratio A:B may rangefrom about 100:1 to about 1:100, or range from about 10:1 to about 1:10.A particular advantage of composites of the invention is the ability tomodify the composition within each A and each B component, as well asthe ratio A:B and physical form of each of A and B, to meet demandsimposed by the end use. There may also be environmental reasons forselecting a particular A or B component, such as disposal constraints.

The composites of the invention may be supported on an “active” supportselected from porous inorganic materials that are stable at temperaturesranging from about 500 to about 1000° C. In this form the inventivecomposites may be referred to as supported composites, or simply“secondary” composites, and these materials are particularly well-suitedfor high-temperature CAR-type processes for O₂ enrichment. Recall thatprimary compositional changes/doping of basic perovskite-type materialsto improve their properties with regard to oxygen exchange have reachedtheir limits. As used herein, the term “secondary composite” meansmechanical combinations on a macro scale of two or more solid materials,one of which is itself a composite (a primary composite of components(A) and (B) as discussed herein), resulting in compositions withspecific goal-oriented macroscopic properties. The phenomenon ofbuilding up/using secondary composites allows for significant unexpected(i) additional O₂-exchange capacity; (ii) improved thermo-chemicalproperties; (iii) appropriate changes in surface-reaction rates; and(iv) improved ceramic-material processing.

Examples of secondary composites of the invention include compositionswhere the “core” O₂-exchange material and the matrix (support) materialare both active with regard to O₂-exchange. For example, secondarycomposites of this invention include one or more primary composites ofthe invention combined with an oxygen-exchange active matrix, which maybe an oxide such as another perovskite that is slightly active, butcontributes desirable mechanical and thermal properties to thecomposite. Composites of the invention optionally include a stabilizingcomponent. It is anticipated that for most composites of the inventionan appropriate binder will have to be utilized.

The stabilizing component functions to maintain the ability of thecomposition to undergo repeated cyclic changes in its crystal structureas temperature, pressure, or both are cycled. Suitable stabilizers arerare earth (lanthanides series) elements and their oxides, such aserbium and erbium oxide.

Binders function to maintain the intended physical shape of thecomposites of the invention under the constraints of the conditions ofuse. These constraints include chemical, electrical, and mechanical, andsuitable binders are materials that substantially match the chemical,electrical, mechanical, and thermo-mechanical properties of thecrystalline ceramic oxides and active support materials. In particularfor non-membrane CAR extrudates to be used under pressure-swingconditions, the binder should allow composites of the invention toachieve a crush strength of at least about 3 kg/cm², or at least about 5kg/cm², as tested by specific techniques and criteria the particularfeatures of which depend greatly on both the shape and geometry of theparticles investigated. Specifically, “buffering” of thethermal-expansion coefficient at O⁻ deficiency conditions (for crystals)allows for maximum Δδ to be utilized by substantially reducing oreliminating the thermo-mechanical-stress gradient across the CAR-typemacroscopic particle. The mechanical strength of composites of theinvention under operating conditions may be improved, for example, bychoosing appropriate supports, inert fillers, fibers and the like.Suitable binders may or may not be chemically active, and include metaloxides that do not undergo significant change in oxidation state,examples of which include the various aluminas, silicas, titanias andzirconia. These materials are well known in the ceramics art.

Active supports useful in the invention include perovskite-likecompounds within general formulas (1), (2), and (3), perovskite-likecompounds within general formulas (4), (5), (6), (7), (8), and (9) andpyrochlores within general formula (10), and combinations thereof. Theactive support may have a particle size (largest dimension) ranging fromabout 1 to about 10,000 microns, or range from about 10 to about 1,000microns. When a binary metal oxide is present with a primary compositeof the invention, the binary metal oxide may overlay the primarycomposite, and the binary metal oxide may have a crystallite sizeranging from about 0.1 to about 0.5 microns. Secondary composites of theinvention may be shaped articles of manufacture, having shape selectedfrom beads, rings, pyramids, extrudates with any cross sectional shapeswith or without holes, honey-combs with uniform channels and monolithswith random porosity and foam structure, and the like.

As with the primary composites of the invention having two or morecrystalline ceramic oxides present, secondary composites of theinvention may be comprised of alternating and densely packed thin layersof oxygen-exchange active materials. Such arrangements provide for anopportunity to (i) buffer thermal-mechanical properties, (ii) increasethe surface-reaction rate by enhancing the accessible surface, and alsothe influence of grain-boundary region effects, (iii) provide forsynergistic effects for increasing the “working capacity” of thematerial.

Intimately arranged physical mixtures of crystallographicallyincompatible structures also have utility as dual-compounded compositematerials of the invention. For example, one or more primary compositesof the invention may be physically dry mixed with a second primarycomposite of the invention, or alternatively with an active matrixmaterial of the type mentioned herein, with optional binder andstabilizer materials.

Specific macroscopic size and system properties of compositions of theinvention of physical/physico-chemical nature that have an unexpectedstrong (positive) influence on enhanced O₂-exchange capacity, includingimproved thermo-chemical properties and accelerated surface-reactionrate are as follows:

-   -   (1) increase in “working capacity” along the O₂-sorption        isotherm (by appropriate change of its slope) via mixing effects        with additional synergies (for example, enhancement of surface        reaction) and by combining O₂-exchange active support materials        into composites with crystalline ceramic oxides of the        invention, which show differences in their active        O₂-partial-pressure regions (select active support materials        having high O⁻ capacity and optionally a linear sorption        isotherm in order to ensure an increased ΔO₂ loading, and its        utilization under CAR-operating conditions);    -   (2) doping of the perovskite-type material of the general        formula A′_(x)A″_(x)B′_(y)B″_(y)O_(3-x) with all the possible        variations in decoding A′, A″, B′, and B″, for several examples,        or other materials to vary either the surface-exchange rate for        O₂ or the rate of chemical oxide-ion diffusion to allow for a        process regime along “non-equilibrium” isotherms, and        increasing, thus, the working capacity, even if the total O₂        capacity remains unchanged/comparatively low. Particularly, this        could be achieved by decreasing the surface reaction rate at        constant high chemical diffusivity (in the crystalline bulk of        the exchange-active material);    -   (3) creating an additional regular macropore-channel system in        secondary single-component perovskite and/or composite        particles, such as extrudates, pellets, and the like, (cf., W.        Geipel and H J. Ullrich, Füllkörper-Taschenbuch, Vulkan Verlag,        Essen, 1991; and R. J. Wijngaarden, A. Kronberg, K. R.        Westerterp, Industrial Catalysis, Wiley-VCh, Weinheim, 1998) and        avoiding formation of mesoporosity with Knudsen-type transport        by utilizing auxiliary pore-forming materials, for example, of        organic character, in the making of secondary-material shapes        that leads to a stochastic macroporosity only. Organic        components of sufficient large size, such as naphthalene and/or        naphthalene-based compounds, which consist of carbon and        hydrogen only, to be burned off completely without strong side        reactions, are desired for this purpose. However, concentration        of pore-creating additives has to be balanced with regard to        efficient removal of CO₂ formed, which could be detrimental to        specific perovskite-type materials;    -   (4) improving the macro-kinetics of CAR processes by utilizing        shape effects in secondary single-component material and/or        composite particles (combining these with enhancement factors        that stem from the additional regular macropore-channel        system.);    -   (5) create “dispersion effects” on external surfaces of        crystalline ceramic oxides or composite particles to enhance the        surface-exchange rate;    -   (6) select crystalline ceramic oxide crystallite size        distributions with their maxima shifted toward lower or higher        crystal sizes, depending on typical rate processes that have to        be identified and characterized for finding composition-specific        optima); and    -   (7) utilize tribochemical and acid-treatment methods to activate        external surface-area regions of crystalline ceramic oxides and        composites including same for enhancing surface reaction by        minimizing the surface barrier.

The particle size for any particular composite of the invention (primaryand secondary) may vary over a large particle size distribution or anarrow particle size distribution, expressed in terms of Gaussiandistribution curves.

Primary composites of the invention are prepared by means known to thoseof skill in the ceramics art. They may be prepared by dispersing thecrystalline ceramic oxides onto an active support with or without theaid of a liquid solvent, and treating the mixture of ceramic oxide andsupport at a temperature ranging from about 600 to about 1,500° C. Theactive inorganic support may be a porous inorganic material comprising aplurality of pores. The porous structure may be formed from a greencomposition comprising additives useful in forming pores in the porousinorganic material and useful to control pore structure of the pores,such as water, organic solvents, celluloses, polymers, synthetic andnaturally formed fibers, starches, metal oxides, and the like, andcombinations thereof. Additives may be selected from water, celluloses,about 0.1 to 1 wt % MgO and about 0.1 to 0.5 wt % TiO₂. Pore sizes mayrange from about 0.001 to 10 microns, or ranging from 0.01 to 1 micron,and specific surface area, as measured in accordance with the BETmethod, may range from about 1 to 200 m²/g, or ranging from 1 to 50m²/g. The metal component is then deposited using physical or chemicalvapor deposition, sputtering, electro-deposition, or like methods.

Methods of Use

A second aspect of the invention are methods of separating a gascomponent from a mixture of gases by either of pressure swingadsorption, thermal swing adsorption, or combination thereof comprisingcontacting a gas mixture with a primary or secondary composite of theinvention. Methods of the invention include those wherein the sorbedoxygen may then be used in situ for reacting with another compound whilestill sorbed, or desorbed and subsequently reacted, or combination ofthese (for example the oxygen may be desorbed from the compositions ofthe invention contained in a vessel and subsequently reacted, in thesame vessel, with a compound to be oxidized). If used in thin membraneform, the composites of the invention may serve as mixed ion andelectron conductors, where O₂ atoms contacting one side of the membraneaccept 2 electrons conducted through the membrane to form O²⁻ ions,while a hydrocarbon flows past the other side of the membrane and reactswith O²⁻ ions conducted through the membrane to form CO, H₂ and release2 electrons. Reactions using the oxygen so sorbed or recovered, such aspartial hydrocarbon oxidation, hydrocarbon steam reforming, hydrocarbonauto-thermal reforming, and the like, in a process mode selected frombatch, semi-continuous, continuous or cyclic operation, are consideredwithin the invention. Aside from the use of the composites of theinvention in these methods, the methods are themselves known to skilledartisans. For example, the method descriptions in U.S. Pat. Nos.6,143,203; 6,379,586 and 6,464,955, and U.S. Pub. Pat. Appl.,2002/0179887 A1 are incorporated herein by reference.

Other methods of the invention include converting a light hydrocarbon(C₅ or less) into hydrogen and carbon monoxide by contacting one or morehydrocarbons with a particulate composition (or composite) of theinvention, carried out in well-known bed-type reaction vessels, wherethe bed of particles is fluidized, semi-fluidized, or non-fluidized.Alternatively, membrane configurations may be employed, as discussedabove. Partial hydrocarbon oxidation reactions are advantageous in thatthey are exothermic, and typically carried out at temperatures rangingfrom about 600 to about 1200° C. In these temperature regimes, thecompositions and composites of the invention are well-suited, since thehigh temperature perovskite cubic structure predominates.

CAR is a Ceramic Auto-thermal Recovery process executed cyclically onconventionally shaped perovskites or related solids in a fixed-bedsorption-type arrangement at high temperature; as a rule at T>700° C.One scheme, illustrated in FIG. 3, illustrates a two-bed system that isrun symmetrically. While exothermic sorption uptake of oxygen takesplace in Bed 1 by passing air through it with a nitrogen-enriched wastegas leaving the bed, endothermic desorption of oxygen and its release asan oxygen-enriched product gas stream takes place in Bed 2, due tooxygen partial pressure decrease as a result of purging the bed with aninert gas. Appropriate heat management of the process system allows foroverall autothermal conditions.

Although the foregoing description is intended to be representative ofthe invention, it is not intended to in any way limit the scope of theappended claims.

1. A composite material comprising components (A) and (B), whereincomponent (A) is selected from crystalline ceramic materials capable offorming a stable, reversible perovskite crystal phase at elevatedtemperatures (T>500° C.), and combinations thereof, and component (B)comprises a metal selected from rhodium (Rh), platinum (Pt), palladium(Pd), nickel (Ni) and silver (Ag), and combinations and alloys of thesemetals.
 2. The composite material of claim 1 wherein component (A) isselected from the group of compounds within general formulas (1), (2),and (3):A_(x)B_(y)O_(3-δ),  (1)A_(x)A′_(x′)B_(y)B′_(y′)O_(3-δ), and  (2)A_(x)A′_(x′)A″_(x″)B_(y)B′_(y′)B″_(y″)O_(3-δ),  (3) and combinationsthereof, wherein: A, A′, and A″ are independently selected from ions ofatoms having atomic number ranging from 57-71, inclusive, a cation ofyttrium, ions of Group 1 atoms, ions of Group 2 atoms, and combinationsof two or more, where Group 1 and Group 2 refer to the periodic table ofelements; B, B′, and B″ are independently selected from d-blocktransition-metal ions selected from Mn, Cr, Fe, Co, Ni, and Cu; x, x′,x″, y, y′, and y″ are each real numbers ranging from 0 to 1.0;x+x′+x″=0.8-1.0; y+y′+y″=1.0; and δ ranges from about 0.05 to about0.30; and with the provisos that: (1) when a Co ion is present at aplurality of B sites, then at least some of the B′ sites are occupied byFe ions, and at least some of the B″ sites are occupied by Ni ions; (2)when a Cu ion is presented at a plurality of B sites, then at least someof the B′ and B″ sites are occupied by one or more of Mn ions, Cr ionsand Fe ions; and (3) when proviso (1) is true, then at least one othercompound within general formulas (1), (2), and (3) is present.
 3. Thecomposite material of claim 1 wherein component (A) is selected fromcompounds within general formulas (4), (5), (6), (7), (8), and (9):A₂BO_(4-δ)  (4)A₂B₂O_(5-δ)  (5)AO(ABO_(3-δ))_(n)  (6)AM₂Cu₃O_(7-δ)  (7)Bi₄V_(2(1-x))Me_(2x)O_(11-3x),  (8)A″B″O₃  (9) wherein: A is independently selected from ions of atomshaving atomic numbers ranging from 57-71, inclusive, a cation ofyttrium, ions of Group 1 atoms, ions of Group 2 atoms, and combinationsof two or more, where Group 1 and Group 2 refer to the periodic table ofelements; B is independently selected from d-block transition metalions; A″ is an ion of Na or Li, and B″ is an ion of W or Mo; M is ametal cation selected from cations of Group 2 atoms of the periodictable of elements; Me is a metal cation selected from cations of Cu, Bi,and Co atoms; x is a real number ranging from 0.01 to 1.0; n ranges from1 to about 10; and δ ranges from about 0.05 to about 0.30.
 4. Thecomposite material of claim 1 wherein component (A) is selected fromcompounds within general formula (10):A₂B₂O_(7-δ)  (10) wherein: A is independently selected from ions ofatoms having atomic numbers ranging from 57-71, inclusive, a cation ofyttrium, ions of Group 1 atoms, ions of Group 2 atoms, and combinationsof two or more, where Group 1 and Group 2 refer to the periodic table ofelements; B is independently selected from d-block transition metalions; and δ ranges from about 0.05 to about 0.30.
 5. The compositematerial of claim 2 wherein A is an ion of atoms having atomic numberranging from 57-71, inclusive; A′ is an Sr ion; and B and B′ areselected from cations of Ni, Co and Fe.
 6. The composite material asclaimed in claim 2 wherein component (A) is a solid solution ofcompounds having the formula La_(x)Sr_(x′)Ni_(y)Co_(y′)Fe_(y″)O_(3-δ),wherein x, x′, y, y′ and y″ are all smaller than 1.05 but greater than0, and one or more compounds within the general formulasA_(x)B_(y)O_(3-δ) and A_(x)A′_(x′)B_(y)B′_(y′)O_(3-δ).
 7. The compositematerial as claimed in claim 6 wherein 0.5<x<1, 0.1<x′<0.5, 0.2<y<0.8,0.2<y′<0.6 and 0.1<y″<0.5.
 8. The composite material as claimed in claim3 wherein component (A) comprises a crystalline ceramic oxide withingeneral formula (7) AM₂Cu₃O_(7-δ).
 9. The composite material as claimedin claim 8 wherein component (A) comprises a crystalline ceramic oxideselected from:Y_(0.5)La_(0.5)BaCaCu₃O_(7-δ)Y_(0.8)La_(0.2)Ba_(0.8)Sr_(1.2)Cu₃O_(7-δ)Y_(0.7)La_(0.3)Ba_(0.8)Sr_(1.2)Cu₃O_(7-δ)Y_(0.9)La_(0.1)Ba_(0.6)Ca_(0.8)Cu₃O_(7-δ) and combinations thereof. 10.The composite material as claimed in claim 1 having a particle sizeranging from about 0.01 to about 100 microns.
 11. The composite materialas claimed in claim 1 having a particle size ranging from about 0.1 toabout 50 microns.
 12. The composite material as claimed in claim 1supported on an active support selected from porous inorganic materials,which are stable at temperatures ranging from about 500 to about 1000°C.
 13. The composite material as claimed in claim 12 wherein the activesupport is selected from binary metal oxides and compounds withingeneral formulas (1), (2), (3), (4), (5), (6), (7), (8), (9), and (10).14. The composite material as claimed in claim 13 wherein said binarymetal oxide is selected from binary metal oxides of d-block transitionmetals and mixtures thereof.
 15. The composite material as claimed inclaim 12 wherein said active support has a particle size ranging fromabout 1 to about 10,000 microns.
 16. The composite material as claimedin claim 15 wherein said particle size ranges from about 10 to about1,000 microns.
 17. The composite material as claimed in claim 1 which isprepared by dispersing the precursors onto an active support with orwithout the aid of a liquid solvent; and treating the precursors andsupport at a temperature ranging from about 600 to about 1,500° C. 18.The composite material as claimed in claim 1 supported on an activesupport to form a secondary composite, wherein said secondary compositehas a shape selected from beads, pellets, saddles, cubes, cylinders,rings, pyramids, extrudates with any cross sectional shapes with orwithout holes, honey-combs with uniform channels and monoliths withrandom porosity and foam structure.
 19. The composite materialcomposition as claimed in claim 18 wherein the shape is selected frommonolith or extrudates with cylindrical shape.
 20. The compositematerial composition as claimed in claim 12 derived from a greencomposition comprising additives useful in forming pores in the porousinorganic material and useful to control pore structure of the pores.21. The composite material composition as claimed in claim 20 whereinsaid additives are selected from water, organic solvents, celluloses,polymers, synthetic and naturally formed fibers, starches and metaloxides.
 22. The composite material composition as claimed in claim 21wherein said additives are selected from water, cellulose, about 0.1 to1 wt % MgO and about 0.1 to 0.5 wt % TiO₂.
 23. The composite materialcomposition as claimed in claim 1 having pore sizes in the range ofabout 0.001 to 10 microns, and surface area in the range of 1 to 200m²/g.
 24. The composite material composition as claimed in claim 23having pore size in the range of 0.01-1 microns and surface area in therange of 1 to 50 m²/g.
 25. The composite material composition as claimedin claim 1 coated on one or more non-porous support materials to achievean increase in performance, and enhancement of thermal and mechanicalproperties of the composition.
 26. The composite material composition asclaimed in claim 12 formed by extrusion.
 28. The composite materialcomposition as claimed in claim 27 wherein said extrusion is performedusing screw extrusion methods.
 29. The composite material composition asclaimed in claim 12 formed by pressing procedures.
 30. The compositematerial as claimed in claim 12 formed by granulation procedures. 31.The composite material composition as claimed in claim 1 having aplurality of macroporous channels.
 32. The composite material as claimedin claim 1 comprising intergrown layers of two or more compounds withingeneral formulas (1), (2), (3), (4), (5), (6), (7), (8), (9), and (10).33. The composition as claimed in claim 1 comprising stacked layers oftwo or more compounds within general formulas (1), (2), (3), (4), (5),(6), (7), (8), (9), and (10).
 34. The composite material as claimed inclaim 12 wherein the active matrix is a compound within general formulaM′O_(n′), wherein M′ is selected from Cu, Co, Ni, Bi, Pb, V, Mn, and Crand n′ ranges from about 1 to about
 5. 35. A method of separating a gascomponent from a mixture of gases by pressure swing adsorption, thermalswing absorption, or combination thereof comprising contacting said gasmixture with the composite material as claimed in claim
 1. 36. A methodof separating a gas component from a mixture of gases by pressure swingadsorption, thermal swing absorption, or combination thereof comprisingcontacting said gas mixture with the composite material as claimed inclaim
 9. 37. A method for converting hydrocarbons into hydrogen andcarbon monoxide by contacting said hydrocarbons with the compositematerial as claimed in claim 1 having oxygen sorbed thereon.
 38. Themethod as claimed in claim 37 wherein reactions of partial oxidation,steam reforming, or auto-thermal reforming, take place in a process modeselected from batch, semi-continuous, continuous or cyclic operations.39. A method for converting hydrocarbons into hydrogen and carbonmonoxide by contacting said hydrocarbons with the composite material asclaimed in claim 9 having oxygen sorbed thereon.
 40. The method asclaimed in claim 39 wherein reactions of partial oxidation, steamreforming, or auto-thermal reforming, take place in a process modeselected from batch, semi-continuous, continuous or cyclic operations.